This invention relates to an apparatus and method for profiling optical disks. Optical disks presently take many forms, and include plastic disks which contain digital data which may represent computer software, music, video, graphics and many other types of digital data. Such disks are presently made in several sizes and are referred to by different names, for example, CD's, compact disks, optical disks, DVD's, and include unrecorded disks which can be “burned”, and disks which are capable of being recorded and then re-recorded. These disks are typically circular. The terms “CD”, “optical disk” and “disk” are used in this application as exemplary of the above structures and are used interchangeably.
Optical disks are also now made and sold which have irregular shapes, and are used for many purposes including business advertising. Such disks can be formed in virtually any shape so long as they will fit into and function in a disk player. One such shape commonly made and distributed is a “business card” disk, which comprises an optical disk which has been cut down in size so that two of the opposing sides are parallel, and the other two opposing sides are convex.
The label, which is typically silk-screened or adhered to the CD, has the general size and shape of the profile to be applied to the CD. The principal requirement for such disks is that the data area exist as a continuous annular area symmetrically positioned around the center hole by which the optical disk is placed on the spindle of a disk player. Such disks are approximately the size of a business card, or somewhat larger.
Known prior art includes an “eyeball” system used by assignee whereby business card CDs were formed by using guillotine chopper blades powered by pneumatic cylinders to chop the edges off of a conventional circular CD after the CD was visually aligned on a base.
U.S. Pat. No. 5,882,655 discloses a profiling apparatus wherein the disk is profiled with reference to a mark (FIG. 3A) or with reference to a notch formed in the base and the edge of the CD to be profiled (FIGS. 4-6).
This invention relates to an automated apparatus and method of profiling CD's quickly and accurately. The profiled CD may be symmetrical or asymmetrical, and the method and apparatus disclosed in this application is capable of taking a circular CD of a given diameter and reducing it in diameter to a smaller circular CD, taking a circular CD and giving it an asymmetrical shape, taking an asymmetrical CD and giving it another asymmetrical shape, or taking an asymmetrical CD and giving it a symmetrical shape, which may be circular or some other symmetrical shape.
The apparatus specifically disclosed herein takes a circular CD and profiles the edge to produce a CD having a non-round, “business card”, outer profile.
The apparatus includes a supply spindle on which is placed a stack of CDs onto which labels have been placed by any suitable process. The CDs are not in any particular orientation insofar as the label is concerned, but are generally randomly oriented. A first vacuum lifter lifts a single CD from the stack and drops the CD on a template which operates on a turntable. This occurs without regard to the orientation of the label. A separate vacuum lifter lifts the CD from the turntable and orients the label to the position where it will be properly cut and shaped by the cutter. This occurs by means of an optical sensor which detects orientation marks, for example, bar code markings, on the surface of the CD. The machine has been programmed to orient the CD to a point in space by using these orientation marks. The point in space corresponds to a particular location relative to the cutter. The oriented CD is placed back on the turntable and clamped in place on the turntable by a novel drift pin arrangement, whereupon the turntable is moved laterally into a machining area where the turntable is rotated relative to a stationary cutter head to form the CD into the desired shape. A guide pin riding along the edge of a surface on the turntable corresponding to the shape to be profiled onto the CD properly positions the CD relative to the stationary cutter as the turntable rotates. A pneumatic cylinder urges the turntable against the guide pin.
After the turntable has made a complete revolution, the CD is unclamped and moved away from the machining area. The CD is removed from the turntable by a vacuum lifter which drops the CD onto a storage spindle where profiled CDs accumulate.
The entire system is controlled by a programmed microprocessor in a conventional manner.
The vacuum lifters are mounted at a ninety-degree angle to each other and move to a neutral location during the machining of the desired profile onto the CD. As an alternative, the steps of lifting the CD from the supply spindle and rotating the CD to orient it for cutting are combined into a single step by placing the optical sensor on the arm which lifts the CD from the supply spindle, so the CD is rotated into the correct orientation during the movement from the supply spindle to the turntable. This compound motion thus accomplishes two steps in one motion.